This chair perfectly supports three key points: legs, buttocks, and lower back, eliminating the need to strain. It's like a large hand gently supporting your back, ensuring your posture always maintains an ideal "S" curve! Even during long hours of exercise or work, sitting in this posture support chair instantly provides a feeling of openness and relieves lumbar fatigue. Long-term use not only improves posture but also helps protect the health of your lumbar spine. It's suitable for office workers, telecommuters, students, seniors concerned about their lumbar health, and pregnant women experiencing lower back pain. Note: This product is designed to support good posture and is therefore made with more durable materials. Some users may experience discomfort in the buttocks. In such cases, please use a cushion.